Paper feed control for a dot-line printer

Abstract

A dot-line printer has a hammer bank carrying a plurality of printing hammers arranged in groups, each group having a predetermined number of printing hammers displaced from one another by predetermined numbers of dot-lines in the direction of paper feed. A shuttle mechanism causes the hammer bank to undergo reciprocating shuttle movements with a reversing period between successive shuttle movements. A character line, covering a predetermined number of dot-lines, is printed over a plurality of shuttle movements, a paper feed mechanism causing the paper to move a predetermined number of dot-lines in the reversing period between shuttle movements. A number of blank dot-lines separate a printed character line from the beginning of the first dot-line of the next character line to be printed. A control mechanism sets the reversing period between successive shuttle movements to be longer than the paper feed time to move the paper to the first dot-line to be printed after the preceding character line has been printed and causes the paper feed to the first dot-line of the next character line to be printed to occur entirely in the reversing period.

What is claimed is: 
     
       1. In a dot-line printer comprising a hammer bank carrying a plurality of dot-printing hammers separated from each other at predetermined intervals along a printing line, and a shuttle mechanism for causing said hammer bank to reciprocate with forward and backward shuttle movements along said printing line, wherein printing occurs as the hammer reciprocates, first means for feeding the paper over predetermined dot-means in the shuttle direction reversing period between successive shuttle movements and second means for feeding the paper after completion of a printed line to the first dot-line of the next line to be printed, there being a plurality of shuttle movements for printing each printing line, wherein the improvement comprises: at least one group of printing hammers containing a predetermined number of printing hammers displaced from one another by predetermined numbers of dot-lines in a direction of paper feed, means for activating said predetermined number of printing hammers constituting said group to thereby simultaneously print a number of dots equal to said predetermined number of hammers, control means for controlling said first and second feed means and said shuttle mechanism such that the reversing period between successive shuttle movements is longer than the time required for carrying out the paper feed after completion of a printed line to the first dot-line of the next line to be printed, and the paper feed from the last printed dot-line of a printed line to the first dot-line of the next line to be printed takes place entirely during a reversing period, wherein the reversing period between shuttle movements is constant without regard to whether the reversing period is during the printing of a printed line or during the paper feed between printed lines, where the number of lines in which said paper is fed is greater between printed lines than during the printing of a printed line.   
     
     
       2. A dot-line printer for printing characters on character lines consisting of a predetermined number of dot-lines, there being a predetermined number of blank dot-lines between successive character lines comprising: a hammer bank consisting of groups of printing hammers, there being a predetermined number of printing hammers in each group, the printing hammers of each group being displaced from one another by predetermined numbers of dot-lines;   a shuttle mechanism for causing said hammer bank to undergo reciprocating shuttle movements, there being a reversing period between successive shuttle movements;   paper feed means for feeding a paper over a predetermined number of dot-lines during each reversing period between shuttle movements for printing a character line, there being a plurality of shuttle movements for printing each character line, and for feeding the paper over said predetermined number of blank lines to first dot-line of the next character line to be printed after the preceding character line has been printed;   timing means for setting the duration of each shuttle movement and the duration of the reversing period and for indicating the presence of the reversing period, said timing means setting the reversing period to be longer than the time necessary for said feed means to feed said paper over said predetermined number of blank dot-lines to the first dot-line of the next character line to be printed; and   said paper feed means including means responsive to said timing means indicating a reversing period after a predetermined number of shuttle movements for causing said paper to move over said predetermined number of blank dot-lines, wherein the reversing period between shuttle movements is constant without regard to whether the reversing period is during the printing of a printed line or during the paper feed between printed lines, where the number of lines in which said paper is fed is greater between printed lines than during the printing of a printed line.   
     
     
       3. The dot-line printer of claim 2 further including a plurality of hammer banks, each comprising at least one group of printing hammers.